/**
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations under the License.
 *
 * Copyright 2012-2015 the original author or authors.
 */
package org.assertj.swing.monitor;

import static java.lang.Boolean.TRUE;
import static org.assertj.core.util.Sets.newHashSet;
import static org.assertj.swing.query.ComponentParentQuery.parentOf;
import static org.assertj.swing.util.Maps.newWeakHashMap;

import java.awt.Component;
import java.awt.EventQueue;
import java.awt.Toolkit;
import java.awt.Window;
import java.util.Collection;
import java.util.Map;
import java.util.Set;

import javax.annotation.Nonnull;

import org.assertj.swing.annotation.RunsInCurrentThread;

/**
 * A mapping of unique event queues to the set of root windows found on each queue.
 *
 * @author Alex Ruiz
 * @author Yvonne Wang
 */
class WindowEventQueueMapping {
  final Map<EventQueue, Map<Window, Boolean>> queueMap = newWeakHashMap();

  void addQueueFor(@Nonnull Toolkit toolkit) {
    Map<Window, Boolean> map = newWeakHashMap();
    queueMap.put(toolkit.getSystemEventQueue(), map);
  }

  void addQueueFor(@Nonnull Component component) {
    EventQueue queue = component.getToolkit().getSystemEventQueue();
    Map<Window, Boolean> windowMapping = queueMap.get(queue);
    if (windowMapping == null) {
      windowMapping = createWindowMapping(queue);
    }
    if (!(component instanceof Window) || parentOf(component) != null) {
      return;
    }
    windowMapping.put((Window) component, TRUE);
  }

  private @Nonnull Map<Window, Boolean> createWindowMapping(EventQueue queue) {
    Map<Window, Boolean> windowMapping = newWeakHashMap();
    queueMap.put(queue, windowMapping);
    return windowMapping;
  }

  @RunsInCurrentThread
  void removeMappingFor(@Nonnull Component component) {
    EventQueue queue = component.getToolkit().getSystemEventQueue();
    removeComponent(component, queue);
    for (EventQueue q : queueMap.keySet()) {
      removeComponent(component, q);
    }
  }

  private void removeComponent(@Nonnull Component component, @Nonnull EventQueue queue) {
    Map<Window, Boolean> windowMapping = queueMap.get(queue);
    if (windowMapping != null) {
      windowMapping.remove(component);
    }
  }

  @Nonnull
  Collection<Window> windows() {
    Set<Window> rootWindows = newHashSet();
    for (EventQueue queue : queueMap.keySet()) {
      rootWindows.addAll(queueMap.get(queue).keySet());
    }
    return rootWindows;
  }

  @Nonnull
  Collection<EventQueue> eventQueues() {
    return queueMap.keySet();
  }
}